The present disclosure relates to compositions and methods for use in subterranean formations.
To produce oil, gas, or other fluids from a subterranean formation, a wellbore is typically drilled in or near the formation. The “borehole” usually refers to the inside wellbore wall, that is, the rock surface or wall that bounds the drilled hole. A drilling fluid, or “mud” which a drilling fluid is also often called, is a specially designed fluid that is circulated in a well bore as the well bore is being drilled to facilitate the drilling operation. The various functions of a drilling fluid include removing drill cuttings from the well bore, cooling and lubricating the drill bit, aiding in support of the drill pipe and drill bit, and providing a hydrostatic head to maintain the integrity of the well bore walls and prevent well blowouts.
A “well” typically includes a wellhead and at least one wellbore from the wellhead penetrating the earth. The “wellhead” is the surface termination of a wellbore, which surface may be on land or on a seabed. A wellbore can be used as a production or injection wellbore. Well treatments and services often include a wide variety of operations that may be performed in oil, gas, geothermal, or water wells, including but not limited to drilling, cementing, completion, and intervention. Specific well service or treatment fluid systems are often selected to optimize the well treatments or services in accordance with the characteristics of a particular geological formation. As used herein, the word “treatment” refers to any treatment for changing a condition of a portion of a wellbore or a subterranean formation adjacent a wellbore; however, the word “treatment” does not necessarily imply any particular treatment purpose. A treatment usually involves introducing a fluid for the treatment, in which case it may be referred to as a treatment fluid, into a well. As used herein, a “treatment fluid” is a fluid used in a treatment. The word “treatment” in the term “treatment fluid” does not necessarily imply any particular treatment or action by the fluid.
A treatment fluid typically comprises water and/or oil, synthetic oil, or other synthetic material or fluid as a base fluid. A number of additives may be included in such drilling fluids to improve certain properties of the fluid. Such additives may include, for example, emulsifiers, weighting agents, fluid-loss additives or fluid-loss control agents, viscosifiers or viscosity control agents, and alkali. Fluid loss typically refers to the undesirable leakage of a fluid phase of any type of fluid into the permeable matrix of a zone, which zone may or may not be a treatment zone. Fluid-loss control refers to treatments, additives, and/or materials designed or used to reduce such undesirable leakage.